Dicksonia sellowiana

Dicksonia sellowiana, the xaxim, or samambaiaçu or imperial samambaiaçu, is an arborescent fern in the family Dicksoniaceae, native to the tropical Americas.

Distribution
The fern is native to Southern Mexico, Central America, and South America.

In the South American Atlantic Forest biome, it is found in: Southeastern Brazil in the states of Minas Gerais, Rio de Janeiro, São Paulo, Paraná, Santa Catarina, and Rio Grande do Sul; in northeast of Argentina within Misiones Province; and in eastern Paraguay.

Description
Dicksonia sellowiana has an erect and cylindrical caudex, reaching sometimes more than 10 m high, the fronds are bipinnate and 2 m long. Due to illegal extraction, the species is at risk of extinction.

Varieties
Dicksonia sellowiana is variable in its form. Variations are sometimes treated as separate varieties, which include:
 * Dicksonia sellowiana var. ghiesbreghtii
 * Dicksonia sellowiana var. gigantea
 * Dicksonia sellowiana var. karsteniana
 * Dicksonia sellowiana var. lobulata